Helicopter window



FIG. 1 is a perspective view of a helicopter window showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a front perspective view thereof;

FIG. 5 is a rear perspective view thereof;

FIG. 6 is a left side elevation view thereof; and

FIG. 7 is a right side elevation view thereof. 

The ornamental design for a helicopter window, as shown. 